This invention is generally directed to systems for controlling the intake and exhaust valves of internal combustion engines and more specifically to a spring assist assembly which functions to positively bias the valves into either an open or closed position once the valves have passed a generally dead center position with regard to the spring assist system. The force provided by the spring assist system may be varied to thereby facilitate adjusting of the timing of the opening and closing of the valves. The spring assemblies are designed to assist in the operation of the intake and exhaust valves in an engine wherein the valves are controlled by a split lobe cam shaft arrangement utilizing a follower which is mounted so as to be engagable with the split lobes to open or close the valves depending upon the position of the cam lobes relative to the follower and wherein each cam follower is resiliently connected to the stem of a respective valve.
2. History of the Related Art
In order to increase the efficiency of the intake and exhaust valves of internal combustion engines, it has been proposed to utilize various biasing techniques for assisting the valves in moving to a closed position. Such a positive biasing of the valves during engine operation is important especially in the field of high speed internal combustion engines. In addition to operating to facilitate and positively control the closure of the valves, the biasing of the valves also stresses the valves' stems relative to their connection with tracking members associated with timing gears or cams which control the opening and closing of the valves.
Some examples of prior art valve biasing mechanisms are disclosed in U.S. Pat. Nos. 1,789,209 to Ausbury, 2,689,557 to Taylor, 3,066,659 to Colton, 3,289,658 to Surovek, Sr. and 3,556,062 to Shermeister.